Thermosensitive recording material

Abstract

A thermosensitive recording material including a support and a thermosensitive coloring layer provided on the support, in which the thermosensitive coloring layer contains (A) a coloring substance, (B) a kraft lignin in which a content of dimethyl disulfide is 2.5 ppm or less and (C) a specific developer.

1 . A thermosensitive recording material comprising:
 a support; and   a thermosensitive coloring layer provided on the support,   wherein the thermosensitive coloring layer contains (A) a coloring substance, (B) a kraft lignin in which a content of dimethyl disulfide is 2.5 ppm or less, and (C) at least one developer of a compound of the following (C-1) group, a compound of the following (C-2) group and a compound of the following (C-3) group,   (C-1) group: a compound represented by the following general formula (I) having a sulfonylurea group   (C-2) group: a compound represented by the following general formula (II) having a sulfonylamide group (a compound represented by the following structural formula (V) is excluded), and   (C-3) group: 4,4′-dihydroxydiphenyl sulfone, 2,4′-dihydroxydiphenylsulfone, bis(3-allyl-4-hydroxyphenyl)sulfone, 4-hydroxy-4′-isoproxydiphenyl sulfone, 4-hydroxy-4′-allyloxydiphenylsulfone and 4-benzyloxy-4′-hydroxydiphenylsulfone   
       
         
           
           
               
               
           
         
         [where R 1  and R 2  represent a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, n1 and n2 represent an integer of 0 to 3, and, in a case where a plurality of R 1 's and a plurality of R 2 's are present, R 1 's and R 2 's may be the same as or different from each other] 
       
       
         
           
           
               
               
           
         
         [where X 1  and X 2  each independently represent —O— or —NH—, R 3  represents a hydrogen atom or —SO 2 —R 4 , R 4  represents a substituted or unsubstituted alkyl group, aralkyl group or aryl group, R 5  and R 6  each independently represent a hydrogen atom or an alkyl group, n3 represents 0 or 1, n4 represents an integer of 0 to 2, and, in a case where a plurality of R 3 's is present, R 3 's may be the same as or different from each other] 
       
       
         
           
           
               
               
           
         
       
     
     
         2 . The thermosensitive recording material according to  claim 1 ,
 wherein, in the thermosensitive coloring layer, a ratio ((B) component/(C) component) of a content of the (B) component to a content of the (C) component is 20/80 to 90/10 in terms of mass ratio.   
     
     
         3 . The thermosensitive recording material according to  claim 1 ,
 wherein the thermosensitive coloring layer contains a compound represented by the following structural formula (III) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         4 . The thermosensitive recording material according to  claim 1 ,
 wherein the thermosensitive coloring layer contains one or more of compounds represented by the following structural formulae (IV) to (VI) as the (C) component,   
       
         
           
           
               
               
           
         
       
       
         
           
           
               
               
           
         
       
     
     
         5 . The thermosensitive recording material according to  claim 1 ,
 wherein the thermosensitive coloring layer contains at least one of the compound of the (C-1) group (a compound represented by the following structural formula (III) is excluded) and the compound of the (C-2) group (a compound represented by the following structural formula (IV) is excluded) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         6 . The thermosensitive recording material according to  claim 1 ,
 wherein the thermosensitive coloring layer contains a compound represented by the following structural formula (VI) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         7 . The thermosensitive recording material according to  claim 2 ,
 wherein the thermosensitive coloring layer contains a compound represented by the following structural formula (III) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         8 . The thermosensitive recording material according to  claim 2 ,
 wherein the thermosensitive coloring layer contains one or more of compounds represented by the following structural formulae (IV) to (VI) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         9 . The thermosensitive recording material according to  claim 2 ,
 wherein the thermosensitive coloring layer contains at least one of the compound of the (C-1) group (a compound represented by the following structural formula (III) is excluded) and the compound of the (C-2) group (a compound represented by the following structural formula (IV) is excluded) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         10 . The thermosensitive recording material according to  claim 2 ,
 wherein the thermosensitive coloring layer contains a compound represented by the following structural formula (VI) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         11 . The thermosensitive recording material according to  claim 3 ,
 wherein the thermosensitive coloring layer contains one or more of compounds represented by the following structural formulae (IV) to (VI) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         12 . The thermosensitive recording material according to  claim 3 ,
 wherein the thermosensitive coloring layer contains at least one of the compound of the (C-1) group (a compound represented by the following structural formula (III) is excluded) and the compound of the (C-2) group (a compound represented by the following structural formula (IV) is excluded) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         13 . The thermosensitive recording material according to  claim 3 ,
 wherein the thermosensitive coloring layer contains a compound represented by the following structural formula (VI) as the (C) component,   
       
         
           
           
               
               
           
         
       
     
     
         14 . A method for producing the thermosensitive recording material according to  claim 1 , comprising:
 a step of forming the thermosensitive coloring layer by applying and drying a coating liquid containing the (A) component, the (B) component and the (C) component on the support.   
     
     
         15 . The production method according to  claim 14 , wherein the (B) component is obtained by causing azeotropy of a kraft lignin in which a content of dimethyl disulfide is more than 2.5 ppm and water and distilling the dimethyl disulfide away. 
     
     
         16 . A method for producing the thermosensitive recording material according to  claim 2 , comprising:
 a step of forming the thermosensitive coloring layer by applying and drying a coating liquid containing the (A) component, the (B) component and the (C) component on the support.   
     
     
         17 . The production method according to  claim 16 , wherein the (B) component is obtained by causing azeotropy of a kraft lignin in which a content of dimethyl disulfide is more than 2.5 ppm and water and distilling the dimethyl disulfide away. 
     
     
         18 . A method for producing the thermosensitive recording material according to  claim 3 , comprising:
 a step of forming the thermosensitive coloring layer by applying and drying a coating liquid containing the (A) component, the (B) component and the (C) component on the support.   
     
     
         19 . The production method according to  claim 18 , wherein the (B) component is obtained by causing azeotropy of a kraft lignin in which a content of dimethyl disulfide is more than 2.5 ppm and water and distilling the dimethyl disulfide away.